Could smart traffic lights stop motorists fuming?

Traffic lights that wirelessly keep track of vehicles could speed up journeys, reduce fuel consumption and improve urban air quality. So say Romanian and US researchers who show that “smart” traffic lights might reduce the time drivers spend waiting at intersections by more than 28% during rush hours.

The researchers recorded peak traffic flow at a major junction in Bucharest, Romania, and then used the distributed computing lab at Rutgers University, New Jersey, US, to model traffic flow.

In the simulations, traffic lights were fed the position and speed of all vehicles on nearby roads and programmed to calculate how to phase colour changes in order to optimise traffic flow. As well as reducing intersection waiting times, the team calculates that CO2 emissions could fall by 6.5%.

Liviu Iftode from Rutgers University and colleagues point out that journey times, fuel consumption and emissions could all be improved further if traffic lights were to transmit information back to vehicles.

Advertisement

Speed warnings

If a set of lights told drivers when they were about to change, “drivers [could] adapt their speed accordingly to avoid useless accelerations or react faster on green,” the team writes in a paper presented at the Vehicular Technology Conference held in Dublin, Ireland, in April 2007.

“Moreover, in-vehicle software could recommend appropriate speeds based on when the current phase will end, and how many cars are already queued,” they write.

For this to work, vehicles must transmit data to the computer system that controls a city’s lights. This is not currently possible, but companies and research groups worldwide are already developing vehicle communications systems that might be adapted for this purpose.

Dash Express is one such car-to-car communication system expected to ship commercially in the US in February 2008. It provides drivers with real-time traffic information using data automatically gathered from other vehicles with Dash Express units, including their current speed and location, via a centralised computer.

Car networks

Researchers at Massachusetts Institute of Technology, Cambridge, US, are testing another vehicle-to-vehicle platform called CarTel that uses Wi-Fi hotspots to send and receive information during a journey.

Another vehicle communication network called CarTorrent developed by a team at University of California in Los Angeles, US, lets drivers within 300 metres of each other exchange data from a range of vehicle sensors.

A European consortium of industrial and academic groups, called Com2React, has even demonstrated a “peer-to-peer” wireless car network that works without any centralised control system.

In theory, each of these systems could be used to relay information to a computer that controls traffic lights.

Cars and Motoring – Learn more about the latest technologies in our comprehensive special report.